One of 14 early-production '63 Corvette Z06s assigned to top road-racers by Chevrolet, Gul
How do you improve on excellence? That was a situation that Grady Davis faced as 1962 wound to a close. Davis, then Gulf Oil's executive VP for research and development, owned a '62 Corvette which Dr. Dick Thompson was driving to win after A/Production win in the big SCCA races across the country, scoring 12 wins in 15 races.
Thanks to the work of Chevrolet's own R&D team, a new-second-generation Vette was in the works for 1963. That's what Davis chose to carry his (and Gulf Oil's) colors for the '63 season, a rolling test bed for Gulf's fuels and lubricants R&D program.
What Davis also chose for his new A/Production race car was the all-new RPO Z06 package, which added these race-grade parts to the production Sting Ray: Big drum-and-shoe brakes with vented backing plates, sintered metallic linings, finned aluminum drums, internal cooling fans and a dual-circuit master cylinder; special suspension front and rear, with stiffer springs, bigger front stabilizer bar and heavy-duty shocks; 36-gallon gas tank; and finned aluminum knock-off wheels. For power, there was the L84 fuel-injected 327, backed by a Borg-Warner T10 four-speed and Chevy's tried-and-true Positraction limited-slip differential.
Race prep included opening the simulated air vents on the hood and adding an early aerodyn
With its first-of-the-line pedigree and impressive list of heavy-duty/racing equipment, Davis' racer was a historic Corvette even before it first rolled on to a race course. It was one of only 14 regular-production Corvettes whose serial numbers were specifically assigned to competition cars before Chevrolet announced RPO Z06's availability on January 1, 1963. It was also the first of two regular-production '63 Sting Rays assigned to Yenko Chevrolet, again specifically for competition. It was also the first Corvette to be prepared with advanced race technology developed especially for the RPO Z06 package, and later adapted to the prototype Corvette Grand Sports.
This car (Chassis No. 2227) and one other went to Davis, while five went to Mickey Thompson. All 14 of the "pre-assigned" Z06s went to top Corvette racers and race teams for the coming '63 season. When it came off the line at St. Louis Assembly in early-October 1962, Gulf Oil personnel picked the car up and drove it to Pittsburgh, where final race preparations were made. Then, it was shipped to Puerto Rico for the first-and, so far, the only-Puerto Rican Grand Prix. With Dr. Dick Thompson at the wheel, "Gulf One" (as it was now called, thanks to its backing and the competition No. 1 it wore) scored its first SCCA A/Production class win. One more race and win-in Marlboro, Maryland's "Refrigerator Bowl" in January 1963-and Gulf One was then prepared in accordance with FIA rules for action at Daytona and Sebring.
"Corvette Sting Ray" logo medallion came off during competition prep, before blue racing s
At Daytona, in the Daytona Continental sports-car race, Thompson piloted it to third place overall (behind two Ferrari GTOs) and first place in the GT3 class. Unfortunately, Gulf One DNF'd at the 12 Hours of Sebring due to transmission failure, after a strong qualifying effort and early-race run.
From then on, Davis entered Gulf One in big SCCA events across the country, just as he did the season before with their '62 Corvette, and-with Thompson at the wheel-it racked up class wins just like the '62 did. In particular, Gulf One took first place overall at the SCCA President's Cup race at Marlboro, Maryland, as well as A/P wins in SCCA races at Danville, Virginia, and Road America at Elkhart Lake, Wisconsin.
Davis, Thompson and Gulf One thrived that season despite two major obstacles. Carroll Shelby's Anglo-American hybrid, the AC Cobra, was appearing in greater numbers for 1963, powered by Ford's own small-block, while its chassis had four-wheel disc brakes-and the entire car weighed about 2/3 what a Z06 Corvette did. Plus, in late January, GM pulled the plug on all its factory-supported racing programs. Nonetheless, Gulf One was the most successful of the 14 "assigned" Z06s.
A pair of big brake-cooling scoops grace Gulf One's tail...
Following the '63 season, Gulf One was succeeded by the next year's racing Corvette (just as it had taken the place of the '62). Davis sold it to Doc Blatchley, who raced it before selling it to Robert Bienerth. He later sold it to Don Pulver, who owned it until 1991.Then, it was sold again-to Rich Mason, who commissioned a total restoration by Carson City, Nevada, Corvette specialist Chet Bunch. Following that, it was sold to Harry Yeaggy, who preserved the restored Gulf One in race-ready condition before selling it a few years ago.
We finally got the chance to see and shoot Gulf One this past January, when it was one of the stars (if not the outright headliner) at the Mecum collector-car auction in Kissimmee, Florida, where it sold for $1,050,000. On hand at Kissimmee was the man who knows more about how Gulf One ran on the track than anyone-Dr. Dick Thompson. We spoke with Dick about the car, which he saw cross the auction block. "That was very nostalgic, and I enjoyed seeing it again. I'd had a lot of fun with it," says Dick.
...all the better to keep the rear drum brakes cool during competition.
How much of an improvement was Gulf One over the '62 that he'd raced for Grady Davis? "It was a very definite change for the better. They'd done a lot of small things that amounted to a lot. "It had some obvious improvements over what I'd been driving" he recalls. "It had better brakes-still not good ones, but better. The streamlining of it was better, and the downforce was more distributed." He goes on, "There was not so much front-end lift as there was on the earlier ones. The main thing was the brakes-they weren't disc brakes, but they were the best drum brakes that you could get."
Also, Thompson recalls that he and the Gulf Oil team were doing more than just racing-in late '62 and early '63, they were also doing R&D for the Corvette Grand Sport. "We did quite a lot of experimenting just before Sebring on various things like the setup of the car, brake linings, and things like that."
When they went racing with Gulf One in 1963, Thompson says they had plenty of hardware with them. "When I was racing full-time for Grady Davis, they had three new engines for every race," says Dick. "They ran 'em on a dyno, and they picked the best one to put in the car, and the other two were spares."
Like its C1 predecessor, Gulf One raced without the OEM bumpers.
What was it like to take Gulf One out on the track for the first time? "It was very pleasant," Dick says with a bit of understatement. "It was in the islands for the Puerto Rico Grand Prix. The handling was very nice, and I was so happy to have some brakes at the end of the race. It was generally a nice car at that point."
Would he have moved from this car to a Grady Davis-owned Grand Sport later in the '63 season? Dick says that was possible-until the GM racing ban hit, which cut the GS's numbers from the planned 125 down to the five prototypes built before the ban. "That was up to Grady Davis. He had connections with the factory by then, and they wanted him to take the new (Z06) car and shake it down, which we did."
Did he ever think that this car would become as valuable as it has? "I can't imagine it, frankly," Dick says. "It was a wonderful car, and things didn't get a lot better than it for a while."
Stock '63 interior was augmented by safety harnesses and rollbar prior to car's first race
RPO Z06 included the RPO L84 fuel-injected 327, with a solid-lifter cam inside.
'63 Z06s like Gulf One got this special dual-circuit master cylinder, which predates regul
Z06 package was a coupe-only item early on, which included the 36-gallon fuel tank that fi
Data File: '63 Chevrolet Corvette Sthing Ray Z06 Coupe
Original Owner: Grady Davis (Executive VP, Gulf Oil Corporation)
Modified production '63 Sting Ray coupe
Modifications: Rear brake cooling scoops, front/rear bumpers removed, cooling vents added to hood (where stock "grilles" were)
Bodywork: Chet Bunch, Carson City, Nevada
Paint: OEM Ermine White with blue racing stripes/numbers; paint preparation & applied by Chet Bunch, Carson City, Nevada
Frame: Modified production '63 Sting Ray
Suspension: Special front/rear suspension (Front) Heavy-duty coil springs, unequal-length A-arms, tubular shocks and stabilizer bar (Rear) Independent with heavy-duty transverse leaf spring and tubular shocks
Steering: Restored OEM GM-Saginaw recirculating-ball, non-power-assisted
Brakes: Restored OEM GM-Delco Moraine drum-and-shoe brakes with 11-inch (OEM size) drums and sintered metallic brake shoes, non-power-assisted
Wheels: RPO P48 cast aluminum knock-off wheels with two-bar spinners
Tires: Goodyear racing tires, 8.00-15 all around
Chevrolet overhead-valve small-block V8 (RPO L84)
Originally built: Chevrolet Motor Division's Flint Engine Plant, Flint, Michigan
Displacement: 327 cubic inches
Compression ratio: 11.25:1
Cylinder heads: Production RPO L84, cast iron
Ignition: OEM GM-Delco points-style ignition
Induction: GM-Rochester mechanical fuel injection system
Camshaft: Production RPO L84 with solid-lifters
Exhaust: Cast iron manifolds with 2-inch pipes
Horsepower: 360 @ 6000 rpm (Advertised)
Torque: 352 ft. /lbs. @ 40000 rpm (Advertised)
Gulf One's (slightly flared) fenderwells are filled with knockoff wheels with two-bar spin
Restored Borg-Warner T10 four-speed manual (RPO M20)
Shifter: Original '63 Sting Ray four-speed shifter with spring-loaded reverse lockout
Rear end: RPO G81 Positraction with 3.70:1 rear gears
Restored modified production '63 Corvette Sting Ray
Modifications: Safety harnesses on drivers and passenger seats, rollbar, electric fuel pump switch on center dash stack
Seats: Production '63 buckets with black vinyl upholstery
Carpets: Production black 80/20 loop-pile
Instrumentation: OEM '63 Sting Ray (0-160 mph speedometer, 0-7000 rpm tachometer with 6500 rpm redline, plus fuel level, oil pressure, ammeter, coolant temperature gauges)
Sound system: See RPO L84
Heater: See RPO L84
A/C: Race it with the windows open